Impedance testing method and system for circuits with electromagnetic shielding film

Abstract

The embodiment of the present invention relates to the field of impedance testing technology, and specifically discloses a method and system for impedance testing of a circuit with an electromagnetic shielding film. The embodiment of the present invention accurately locates and identifies the circuit board to be tested that has been placed and is affixed with an electromagnetic shielding film; when it is in a standard placement state, it visually scans and analyzes the defects of the electromagnetic shielding film; when it is in a standard appearance state, it performs a circuit impedance test and collects impedance test data; based on the impedance specification data, it analyzes and compares the impedance test data and records the impedance test results; according to a preset test report template, it fills the impedance test results with data, generates and uploads an impedance test report. It is capable of performing accurate positioning and identification, visual scanning and defect analysis of the electromagnetic shielding film, and then performing a circuit impedance test, recording the impedance test results, generating and uploading an impedance test report, thereby achieving standard, reliable, and efficient impedance testing for circuits with electromagnetic shielding film.

Description

Technical Field

[0001] The present invention belongs to the technical field of impedance testing, and in particular relates to an impedance testing method and system for a circuit with an electromagnetic shielding film. Background Art

[0002] In a DC circuit, resistance is the sole determinant of current flow. However, in an AC circuit, in addition to resistance, capacitance and inductance also affect current flow. Impedance is a measure of the resistance to current flow in an AC circuit. This includes not only resistance but also reactance due to capacitance and inductance. Impedance testing is a technique for measuring the resistance of components in an electronic circuit or system to an AC signal.

[0003] In the prior art, there are many testing methods for line impedance testing, including vector network analyzers, LCR meters, and impedance analyzers. However, there is no standard, reliable, and efficient testing method for impedance testing of lines with electromagnetic shielding film. Summary of the Invention

[0004] The purpose of the embodiments of the present invention is to provide a method and system for testing the impedance of a circuit with an electromagnetic shielding film, aiming to solve the problems raised in the background technology.

[0005] To achieve the above objectives, the embodiments of the present invention provide the following technical solutions:

[0006] A method for measuring the impedance of a circuit with an electromagnetic shielding film, the method specifically comprising the following steps:

[0007] The placed circuit board with electromagnetic shielding film is photographed horizontally and vertically, and accurately positioned and identified to determine whether it is in the standard placement state;

[0008] When the circuit board is in a standard placement state, visually scanning and defect analysis of the electromagnetic shielding film of the circuit board to be tested is performed to determine whether it is in a standard appearance state;

[0009] When in a standard appearance state, the device automatically connects to multiple test points of the circuit board to be tested, executes a preset frequency sweep task to perform line impedance testing, and collects impedance test data;

[0010] Analyze and compare the impedance test data based on the preset impedance specification data, and record the impedance test results;

[0011] According to the preset test report template, the impedance test results are filled with data, and an impedance test report is generated and uploaded.

[0012] As a further limitation of the technical solution of the embodiment of the present invention, the horizontal and vertical alignment photography of the placed circuit board to be tested with the electromagnetic shielding film affixed thereto, and the precise positioning and identification to determine whether it is in the standard placement state specifically include the following steps:

[0013] Placement monitoring is performed on the circuit board to be tested with the electromagnetic shielding film affixed thereto, and after placement is completed, horizontal shooting signals and vertical shooting signals are generated;

[0014] Performing horizontal shooting of the circuit board to be tested according to the horizontal shooting signal to obtain a horizontal shooting image;

[0015] According to the vertical shooting signal, vertically shoot the circuit board to be tested to obtain a vertical shooting image;

[0016] Perform height recognition on the horizontally shot image and perform position recognition on the vertically shot image to determine whether it is in a standard placement state.

[0017] As a further limitation of the technical solution of the embodiment of the present invention, when the circuit board is in the standard placement state, visually scanning and defect analysis of the electromagnetic shielding film of the circuit board to be tested to determine whether it is in the standard appearance state specifically includes the following steps:

[0018] When in a standard placement state, a visual scanning instruction is generated;

[0019] Performing a visual scan of the electromagnetic shielding film on the circuit board to be tested according to the visual scanning instruction to obtain a plurality of visual scanning images;

[0020] Cutting and splicing the plurality of visual scan images to obtain a standard visual image;

[0021] Performing feature recognition on the standard visual image and recording feature recognition information;

[0022] Perform defect analysis on the feature identification information to determine whether it is in a standard appearance state.

[0023] As a further limitation of the technical solution of the embodiment of the present invention, when in the standard appearance state, automatically connecting multiple test points of the circuit board to be tested, executing a preset frequency sweep task to perform line impedance testing, and collecting impedance test data specifically include the following steps:

[0024] When in the standard appearance state, generate a test connection instruction;

[0025] Automatically connect multiple test points of the circuit board to be tested according to the test connection instruction;

[0026] Execute the preset frequency sweep task to perform line impedance test;

[0027] During the line impedance test, impedance test data is collected.

[0028] As a further limitation of the technical solution of the embodiment of the present invention, the analyzing and comparing the impedance test data based on the preset impedance specification data and recording the impedance test results specifically include the following steps:

[0029] Performing impedance analysis on the impedance test data to obtain characteristic impedance data;

[0030] Performing standing wave ratio analysis on the impedance test data to obtain standing wave ratio data;

[0031] Based on the preset impedance specification data, the characteristic impedance data and the standing wave ratio data are compared, and the impedance test results are recorded.

[0032] As a further limitation of the technical solution of the embodiment of the present invention, the step of filling data of the impedance test result according to the preset test report template, generating and uploading the impedance test report specifically includes the following steps:

[0033] Get impedance test time;

[0034] Generate a current report template according to the impedance test time and a preset test report template;

[0035] Filling data of the impedance test result in the current report template to generate an impedance test report;

[0036] Upload the impedance test report according to the preset upload address.

[0037] An impedance testing system for a circuit with an electromagnetic shielding film, the system comprising a precise positioning and identification unit, a shielding film defect analysis unit, a circuit impedance testing unit, an impedance test analysis unit, and a report generation and uploading unit, wherein:

[0038] The precise positioning and identification unit is used to take horizontal and vertical alignment photos of the placed circuit board to be tested with the electromagnetic shielding film attached, and to perform precise positioning and identification to determine whether it is in the standard placement state;

[0039] a shielding film defect analysis unit, configured to perform visual scanning and defect analysis of the electromagnetic shielding film of the circuit board to be tested when the circuit board is in a standard placement state, to determine whether the shielding film is in a standard appearance state;

[0040] A line impedance test unit, configured to automatically connect to multiple test points of the circuit board to be tested when in a standard appearance state, execute a preset frequency sweep task to perform line impedance testing, and collect impedance test data;

[0041] An impedance test analysis unit, configured to analyze and compare the impedance test data based on preset impedance specification data, and record the impedance test results;

[0042] The report generation and uploading unit is used to fill in the data of the impedance test results according to the preset test report template, generate and upload the impedance test report.

[0043] As a further limitation of the technical solution of the embodiment of the present invention, the precise positioning and identification unit specifically includes:

[0044] A placement monitoring module is used to monitor the placement of the circuit board to be tested with the electromagnetic shielding film affixed thereto, and generate a horizontal shooting signal and a vertical shooting signal after the placement is completed;

[0045] a horizontal shooting module, configured to shoot horizontally the circuit board to be tested according to the horizontal shooting signal to obtain a horizontal shooting image;

[0046] A vertical shooting module, configured to shoot vertically the circuit board to be tested according to the vertical shooting signal to obtain a vertical shooting image;

[0047] The positioning and recognition module is used to perform height recognition on the horizontally shot image and perform positioning recognition on the vertically shot image to determine whether it is in a standard placement state.

[0048] As a further limitation of the technical solution of the embodiment of the present invention, the shielding film defect analysis unit specifically includes:

[0049] A scanning instruction generation module, used for generating a visual scanning instruction when in a standard placement state;

[0050] A visual scanning module, configured to perform a visual scan of the electromagnetic shielding film of the circuit board to be tested according to the visual scanning instruction, and obtain a plurality of visual scanning images;

[0051] A cutting and splicing module, used for cutting and splicing a plurality of the visual scanned images to obtain a standard visual image;

[0052] A feature recognition module, configured to perform feature recognition on the standard visual image and record feature recognition information;

[0053] The defect analysis module is used to perform defect analysis on the feature recognition information to determine whether it is in a standard appearance state.

[0054] As a further limitation of the technical solution of the embodiment of the present invention, the report generation and uploading unit specifically includes:

[0055] Time acquisition module, used to obtain impedance test time;

[0056] A template generating module, configured to generate a current report template according to the impedance test time and a preset test report template;

[0057] A data filling module, configured to fill data of the impedance test result in the current report template to generate an impedance test report;

[0058] The report uploading module is used to upload the impedance test report according to a preset upload address.

[0059] Compared with the prior art, the present invention has the following beneficial effects:

[0060] The embodiment of the present invention accurately locates and identifies a circuit board to be tested that has been placed and is affixed with an electromagnetic shielding film; visually scans and analyzes the electromagnetic shielding film for defects when in a standard placement state; performs a line impedance test and collects impedance test data when in a standard appearance state; analyzes and compares the impedance test data based on impedance specification data and records the impedance test results; and fills in the impedance test results according to a preset test report template, generating and uploading an impedance test report. The system is capable of performing accurate positioning and identification, visually scanning and analyzing the electromagnetic shielding film for defects, performing line impedance testing, recording the impedance test results, and generating and uploading an impedance test report, thereby achieving standard, reliable, and efficient impedance testing for circuits affixed with electromagnetic shielding film. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention.

[0062] Figure 1 A flow chart of a method provided by an embodiment of the present invention is shown.

[0063] Figure 2 A flow chart showing precise positioning and identification in the method provided by an embodiment of the present invention is shown.

[0064] Figure 3 A flow chart of electromagnetic shielding film defect analysis in the method provided by an embodiment of the present invention is shown.

[0065] Figure 4 A flow chart of line impedance testing in the method provided by an embodiment of the present invention is shown.

[0066] Figure 5 A flow chart of recording impedance test results in the method provided by an embodiment of the present invention is shown.

[0067] Figure 6A flow chart of generating an impedance test report in the method provided by an embodiment of the present invention is shown.

[0068] Figure 7 The application architecture diagram of the system provided by the embodiment of the present invention is shown.

[0069] Figure 8 The figure shows a structural block diagram of a precise positioning and identification unit in a system provided by an embodiment of the present invention.

[0070] Figure 9 A structural block diagram of a shielding film defect analysis unit in a system provided by an embodiment of the present invention is shown.

[0071] Figure 10 It shows a structural block diagram of a report generation and uploading unit in a system provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0072] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0073] It is understandable that in the prior art, there are many testing methods for line impedance testing, including vector network analyzers, LCR meters, and impedance analyzers. However, there is no standard, reliable, and efficient testing method for impedance testing of lines with electromagnetic shielding film.

[0074] To solve the above problems, the embodiment of the present invention performs horizontal and vertical alignment photography of the placed circuit board to be tested with an electromagnetic shielding film, and performs precise positioning and identification to determine whether it is in a standard placement state; when it is in the standard placement state, the electromagnetic shielding film of the circuit board to be tested is visually scanned and defect analyzed to determine whether it is in a standard appearance state; when it is in the standard appearance state, multiple test points of the circuit board to be tested are automatically connected, a preset frequency scanning task is performed to perform line impedance testing, and impedance test data is collected; based on preset impedance specification data, the impedance test data is analyzed and compared, and the impedance test results are recorded; according to a preset test report template, the impedance test results are filled with data, and an impedance test report is generated and uploaded. The embodiment of the present invention is capable of performing precise positioning and identification, visual scanning and defect analysis of the electromagnetic shielding film, and then performing line impedance testing, recording impedance test results, and generating and uploading impedance test reports, thereby achieving standard, reliable, and efficient impedance testing for circuits with electromagnetic shielding film.

[0075] Figure 1 A flow chart of a method provided by an embodiment of the present invention is shown.

[0076] Specifically, a method for measuring the impedance of a circuit with an electromagnetic shielding film is provided, the method comprising the following steps:

[0077] In step S101 , the placed circuit board to be tested with the electromagnetic shielding film affixed thereto is photographed in a horizontal and vertical alignment manner, and accurately positioned and identified to determine whether it is in a standard placement state.

[0078] In an embodiment of the present invention, during the process of manual or automatic placement of a circuit board to be tested with an electromagnetic shielding film, real-time placement monitoring is performed, and after the placement is completed, a horizontal shooting signal and a vertical shooting signal are generated, and then according to the horizontal shooting signal, the circuit board to be tested is horizontally shot on one side of the circuit board to be tested to obtain a horizontal shooting image, and according to the vertical shooting signal, the circuit board to be tested is vertically shot on the top of the circuit board to be tested to obtain a vertical shooting image, and by performing height recognition of the top of the circuit board to be tested on the horizontal shooting image and positioning recognition of the circuit board to be tested on the vertical shooting image, it is determined whether it is in a standard placement state, specifically: when the height recognition and positioning recognition are both normal, it is determined to be in a standard placement state; when the height recognition and / or positioning recognition are abnormal, it is determined to be not in a standard placement state.

[0079] Specifically, Figure 2 A flow chart showing precise positioning and identification in the method provided by an embodiment of the present invention is shown.

[0080] Among them, in the preferred embodiment provided by the present invention, the horizontal and vertical alignment shooting of the placed circuit board to be tested with the electromagnetic shielding film affixed thereto, and the precise positioning and identification to determine whether it is in the standard placement state specifically include the following steps:

[0081] Step S1011, placing and monitoring the circuit board to be tested with the electromagnetic shielding film affixed thereto, and generating a horizontal shooting signal and a vertical shooting signal after the placement is completed;

[0082] Step S1012: horizontally photographing the circuit board to be tested according to the horizontal photographing signal to obtain a horizontal photographing image;

[0083] Step S1013: vertically photograph the circuit board to be tested according to the vertical photographing signal to obtain a vertical photographing image;

[0084] Step S1014: performing height recognition on the horizontally shot image and positioning recognition on the vertically shot image to determine whether the device is in a standard placement state.

[0085] Furthermore, the method of performing height recognition on the horizontally shot image and positioning recognition on the vertically shot image to determine whether the device is in the standard placement state specifically includes the following steps:

[0086] Perform edge detection on the matrix of the horizontally shot image to find the highest and lowest positions of the edge points in the horizontally shot image and calculate the height of the image. The corresponding process has the following relationship:

[0087] ;

[0088] in, Indicates the horizontal height, Indicates logical "existence", denote the rows and columns of the edge matrix respectively, Represents the edge matrix E Middle i Rank j The value of the column;

[0089] Perform edge detection on the matrix of the vertically shot image, and calculate the weighted center position of the image by weighting the positions of the edge points. The corresponding process has the following relationship:

[0090] ;

[0091] in, represents the horizontal and vertical coordinates, represents the weighted horizontal coordinates of all edge points in the image, represents the weighted ordinates of all edge points in the image, represents the number of edge points, Indicates the n The weight of the edge points, Indicates the n The coordinates of the edge points,

[0092] Calculate the variance of the horizontal and vertical coordinates of the edge points around the weighted center position to measure the stability of the center position. The corresponding process has the following relationship:

[0093] ;

[0094] in, represents the variance of the horizontal coordinates of the edge points, represents the variance of the vertical coordinates of the edge points,

[0095] Define the height threshold, positioning tolerance, and variance tolerance to determine whether the circuit board is in the standard placement state. The standard placement judgment conditions are as follows:

[0096] ;

[0097] in, represents the height threshold, Indicates tolerance, Represents the height and width of the image respectively, represents the variance threshold;

[0098] If all the above conditions are met, the circuit board is in the standard placement state.

[0099] Furthermore, the impedance testing method for a circuit with an electromagnetic shielding film affixed thereto further comprises the following steps:

[0100] Step S102 : When the circuit board is in the standard placement state, visual scanning and defect analysis of the electromagnetic shielding film of the circuit board to be tested are performed to determine whether the circuit board is in the standard appearance state.

[0101] In an embodiment of the present invention, when in a standard placement state, a visual scanning instruction is generated. At this time, according to the visual scanning instruction, the electromagnetic shielding film of the circuit board to be tested is visually scanned along the horizontal extension of the circuit board to be tested, and multiple visual scanning images are obtained. The multiple visual scanning images are then cut and spliced to obtain a standard visual image of the circuit board to be tested. By performing feature recognition of size, color, and shape on the standard visual image, recording the feature recognition information, and then performing defect analysis on the feature recognition information, it is determined whether it is in a standard appearance state. Specifically: when there are no defects such as cracks, bubbles, foreign matter, etc. in the defect analysis, it is determined to be in a standard appearance state; when there are defects such as cracks, bubbles and / or foreign matter in the defect analysis, it is determined that it is not in a standard appearance state.

[0102] Specifically, Figure 3 A flow chart of electromagnetic shielding film defect analysis in the method provided by an embodiment of the present invention is shown.

[0103] Among them, in the preferred embodiment provided by the present invention, when the circuit board is in the standard placement state, visual scanning and defect analysis of the electromagnetic shielding film of the circuit board to be tested to determine whether it is in the standard appearance state specifically includes the following steps:

[0104] Step S1021, when in the standard placement state, generating a visual scanning instruction;

[0105] Step S1022: performing a visual scan of the electromagnetic shielding film of the circuit board to be tested according to the visual scanning instruction to obtain a plurality of visual scanning images;

[0106] Step S1023, cutting and splicing the plurality of visual scan images to obtain a standard visual image;

[0107] Step S1024, performing feature recognition on the standard visual image and recording feature recognition information;

[0108] Step S1025: perform defect analysis on the feature recognition information to determine whether it is in a standard appearance state. The corresponding process has the following relationship:

[0109] ;

[0110] in, Indicates that defect analysis operations are performed based on the feature recognition information set extracted from the standard visual image, the feature information set of the standard template, and the additional feature set extracted from the standard visual image. Represents a set of feature recognition information extracted from standard visual images, Represents the feature information set of the standard template, represents a set of additional features extracted from standard visual images, Represents a set of all feature points in the feature recognition information set, Indicates the l Feature identification information, Indicates the l Template feature information, Indicates the l Additional feature information, Indicates the l Feature recognition information and l The distance between the template feature information, Indicates the l Additional feature information is used for weight calculation. Represent the weight coefficients of balancing feature recognition information and additional feature information respectively; Indicates the threshold value, used to determine whether it is in the standard appearance state; Indicates the number of features in the feature recognition information set;

[0111] In the above steps, the present invention comprehensively considers multiple feature information of the standard visual image, not only simple feature recognition information, but also additional features, such as edge features, texture features, etc., which makes the analysis results more comprehensive and accurate.

[0112] Set with adjustable weight coefficient This can be adjusted based on actual needs. This allows for flexible adjustment of the influence of feature identification information and additional feature information based on the importance of different features in real applications, providing greater adaptability. The final judgment is made using a simple threshold. This approach is intuitive and easy to understand, implement, and debug. Furthermore, by setting the threshold, the judgment criteria can be flexibly adjusted to suit different application needs.

[0113] Furthermore, the impedance testing method for a circuit with an electromagnetic shielding film affixed thereto further comprises the following steps:

[0114] Step S103 , when in a standard appearance state, automatically connect multiple test points of the circuit board to be tested, execute a preset frequency sweep task to perform line impedance testing, and collect impedance test data.

[0115] In an embodiment of the present invention, when in a standard appearance state, a test connection instruction is generated. At this time, according to the test connection instruction, multiple test points of the circuit board to be tested are automatically connected through multiple probes. After the test connection is completed, a preset frequency scanning task is executed to perform a line impedance test, and during the line impedance test process, impedance test data is collected.

[0116] Specifically, Figure 4 A flow chart of line impedance testing in the method provided by an embodiment of the present invention is shown.

[0117] Among them, in the preferred embodiment provided by the present invention, when in the standard appearance state, automatically connecting multiple test points of the circuit board to be tested, executing a preset frequency sweep task to perform line impedance testing, and collecting impedance test data specifically include the following steps:

[0118] Step S1031, when in the standard appearance state, generating a test connection instruction;

[0119] Step S1032: automatically connecting multiple test points of the circuit board to be tested according to the test connection instruction;

[0120] Step S1033, executing a preset frequency sweep task to perform line impedance testing;

[0121] The method for executing a preset frequency sweep task to perform line impedance testing specifically includes the following steps:

[0122] The frequency sweep signal is generated by the frequency sweep signal generation formula f and time t The corresponding process of the sinusoidal signal under the following relationship exists:

[0123] ;

[0124] in, Indicates the frequency f and time t The sinusoidal signal below, represents the amplitude of the signal, Indicates frequency, Indicates time, Indicates the initial phase of the signal;

[0125] Input a sinusoidal signal into the test circuit board and obtain the voltage and current signals through measurement. The corresponding process has the following relationship:

[0126] ;

[0127] ;

[0128] in, Indicates the frequency f The voltage signal measured below is Indicates the frequency f The current signal measured below is represent the amplitudes of voltage and current signals respectively, denote the phase angles of voltage and current signals respectively, represents the phase portion of the voltage response, represents the imaginary unit, represents the phase portion of the current response, represents the exponential function;

[0129] By using the impedance calculation formula, the voltage and current signals are divided by their amplitudes, and the phase difference is calculated to obtain the impedance value at the frequency. The corresponding process has the following relationship:

[0130] ;

[0131] in, Indicates the frequency f The impedance calculated below.

[0132] Step S1034: During the line impedance test process, impedance test data is collected.

[0133] Furthermore, the impedance testing method for a circuit with an electromagnetic shielding film affixed thereto further comprises the following steps:

[0134] Step S104: analyzing and comparing the impedance test data based on the preset impedance specification data, and recording the impedance test results.

[0135] In an embodiment of the present invention, impedance analysis is performed on the impedance test data to obtain characteristic impedance data, and standing wave ratio analysis is performed on the impedance test data to obtain standing wave ratio data. Then, based on preset impedance specification data, the characteristic impedance data and the standing wave ratio data are compared to record the impedance test results.

[0136] Specifically, Figure 5 A flow chart of recording impedance test results in the method provided by an embodiment of the present invention is shown.

[0137] Among them, in the preferred embodiment provided by the present invention, the impedance test data is analyzed and compared based on the preset impedance specification data, and the impedance test results are recorded, which specifically includes the following steps:

[0138] Step S1041, performing impedance analysis on the impedance test data to obtain characteristic impedance data;

[0139] Step S1042, performing standing wave ratio analysis on the impedance test data to obtain standing wave ratio data;

[0140] Step S1043 : Based on the preset impedance specification data, the characteristic impedance data and the standing wave ratio data are compared, and the impedance test result is recorded.

[0141] Furthermore, the impedance testing method for a circuit with an electromagnetic shielding film affixed thereto further comprises the following steps:

[0142] Step S105: Fill in the data of the impedance test result according to the preset test report template, generate and upload the impedance test report.

[0143] In an embodiment of the present invention, the impedance test time is obtained, and then the current report template is generated according to the impedance test time and the preset test report template. The impedance test result is content-identified and data of the impedance test result is filled in the current report template to generate an impedance test report. The impedance test report is then uploaded according to the preset upload address.

[0144] Specifically, Figure 6 A flow chart of generating an impedance test report in the method provided by an embodiment of the present invention is shown.

[0145] Among them, in the preferred embodiment provided by the present invention, the data filling of the impedance test results according to the preset test report template, generating and uploading the impedance test report specifically includes the following steps:

[0146] Step S1051, obtaining impedance test time;

[0147] Step S1052: Generate a current report template according to the impedance test time and a preset test report template;

[0148] Step S1053, filling data of the impedance test result in the current report template to generate an impedance test report;

[0149] Step S1054: Upload the impedance test report according to the preset upload address.

[0150] Further, Figure 7 The application architecture diagram of the system provided by the embodiment of the present invention is shown.

[0151] In another preferred embodiment of the present invention, an impedance testing system for a circuit with an electromagnetic shielding film is provided, comprising:

[0152] The precise positioning and identification unit 101 is used to perform horizontal and vertical alignment photography on the placed circuit board to be tested with the electromagnetic shielding film attached thereto, and to perform precise positioning and identification to determine whether it is in a standard placement state.

[0153] In an embodiment of the present invention, during the manual or automatic placement of the circuit board to be tested with the electromagnetic shielding film affixed thereto, the precise positioning and identification unit 101 performs real-time placement monitoring, and after the placement is completed, generates a horizontal shooting signal and a vertical shooting signal, and then according to the horizontal shooting signal, the circuit board to be tested is horizontally shot on one side of the circuit board to be tested to obtain a horizontal shooting image, and according to the vertical shooting signal, the circuit board to be tested is vertically shot on the top of the circuit board to be tested to obtain a vertical shooting image, and by performing height recognition of the top of the circuit board to be tested on the horizontal shooting image and positioning recognition of the circuit board to be tested on the vertical shooting image, it is determined whether it is in the standard placement state, specifically: when the height recognition and positioning recognition are normal, it is determined to be in the standard placement state; when the height recognition and / or positioning recognition are abnormal, it is determined to be not in the standard placement state.

[0154] Specifically, Figure 8 FIG. 1 shows a structural block diagram of the precise positioning and identification unit 101 in the system provided by an embodiment of the present invention.

[0155] In a preferred embodiment of the present invention, the precise positioning and identification unit 101 specifically includes:

[0156] A placement monitoring module 1011 is used to monitor the placement of the circuit board to be tested with the electromagnetic shielding film attached thereto, and generate a horizontal shooting signal and a vertical shooting signal after the placement is completed;

[0157] A horizontal shooting module 1012 is configured to shoot horizontally the circuit board to be tested according to the horizontal shooting signal to obtain a horizontal shooting image;

[0158] A vertical shooting module 1013 is configured to shoot vertically the circuit board to be tested according to the vertical shooting signal to obtain a vertical shooting image;

[0159] The positioning recognition module 1014 is used to perform height recognition on the horizontally shot image and perform positioning recognition on the vertically shot image to determine whether it is in a standard placement state.

[0160] Furthermore, the impedance testing system for the circuit with the electromagnetic shielding film also includes:

[0161] The shielding film defect analysis unit 102 is used to perform visual scanning and defect analysis on the electromagnetic shielding film of the circuit board to be tested when the circuit board is in a standard placement state, to determine whether the circuit board is in a standard appearance state.

[0162] In an embodiment of the present invention, when in a standard placement state, the shielding film defect analysis unit 102 generates a visual scanning instruction. At this time, according to the visual scanning instruction, the electromagnetic shielding film of the circuit board to be tested is visually scanned along the horizontal extension of the circuit board to be tested, and multiple visual scanning images are obtained. The multiple visual scanning images are then cut and spliced to obtain a standard visual image of the circuit board to be tested. By performing feature recognition of size, color, and shape on the standard visual image, recording the feature recognition information, and then performing defect analysis on the feature recognition information, it is determined whether it is in a standard appearance state. Specifically: when there are no defects such as cracks, bubbles, foreign matter, etc. in the defect analysis, it is determined to be in a standard appearance state; when there are defects such as cracks, bubbles and / or foreign matter in the defect analysis, it is determined that it is not in a standard appearance state.

[0163] Specifically, Figure 9 A structural block diagram of the shielding film defect analysis unit 102 in the system provided by an embodiment of the present invention is shown.

[0164] Among them, in the preferred embodiment provided by the present invention, the shielding film defect analysis unit 102 specifically includes:

[0165] The scanning instruction generating module 1021 is used to generate a visual scanning instruction when in the standard placement state;

[0166] A visual scanning module 1022 is configured to perform a visual scan of the electromagnetic shielding film of the circuit board to be tested according to the visual scanning instruction to obtain a plurality of visual scanning images;

[0167] A cutting and splicing module 1023 is used to cut and splice the multiple visual scan images to obtain a standard visual image;

[0168] A feature recognition module 1024 is configured to perform feature recognition on the standard visual image and record feature recognition information;

[0169] The defect analysis module 1025 is used to perform defect analysis on the feature recognition information to determine whether it is in a standard appearance state.

[0170] Furthermore, the impedance testing system for the circuit with the electromagnetic shielding film also includes:

[0171] The line impedance testing unit 103 is used to automatically connect multiple test points of the circuit board to be tested when it is in a standard appearance state, execute a preset frequency scanning task to perform line impedance testing, and collect impedance test data.

[0172] In an embodiment of the present invention, when in a standard appearance state, the line impedance test unit 103 generates a test connection instruction. At this time, according to the test connection instruction, multiple test points of the circuit board to be tested are automatically connected through multiple probes. After completing the test connection, the preset frequency scanning task is executed to perform the line impedance test, and during the line impedance test process, the impedance test data is collected.

[0173] The impedance test analysis unit 104 is used to analyze and compare the impedance test data based on preset impedance specification data and record the impedance test results.

[0174] In an embodiment of the present invention, the impedance test analysis unit 104 performs impedance analysis on the impedance test data to obtain characteristic impedance data, and performs standing wave ratio analysis on the impedance test data to obtain standing wave ratio data, and then compares the characteristic impedance data and the standing wave ratio data based on preset impedance specification data to record the impedance test results.

[0175] The report generation and uploading unit 105 is used to fill in the data of the impedance test result according to the preset test report template, and generate and upload the impedance test report.

[0176] In an embodiment of the present invention, the report generation and uploading unit 105 obtains the impedance test time, and then generates a current report template according to the impedance test time and the preset test report template. By performing content recognition on the impedance test result, the impedance test result is filled with data in the current report template to generate an impedance test report, and then the impedance test report is uploaded according to the preset upload address.

[0177] Specifically, Figure 10 It shows a structural block diagram of the report generation and uploading unit 105 in the system provided by an embodiment of the present invention.

[0178] In a preferred embodiment of the present invention, the report generation and uploading unit 105 specifically includes:

[0179] A time acquisition module 1051 is used to obtain the impedance test time;

[0180] A template generating module 1052 is configured to generate a current report template according to the impedance test time and a preset test report template;

[0181] A data filling module 1053 is configured to fill data of the impedance test result in the current report template to generate an impedance test report;

[0182] The report uploading module 1054 is used to upload the impedance test report according to a preset upload address.

[0183] It should be understood that, although the various steps in the flow chart of each embodiment of the present invention are shown in sequence according to the indication of the arrows, these steps are not necessarily performed in sequence according to the order indicated by the arrows. Unless otherwise specified herein, the execution of these steps is not strictly limited in order, and these steps can be performed in other orders. Moreover, at least a portion of the steps in each embodiment may include a plurality of sub-steps or a plurality of stages, and these sub-steps or stages are not necessarily performed at the same time, but can be performed at different times, and the execution order of these sub-steps or stages is not necessarily performed in sequence, but can be performed in turn or alternately with at least a portion of other steps or sub-steps or stages of other steps.

[0184] Those skilled in the art will appreciate that all or part of the processes in the above-described method embodiments can be implemented by instructing the relevant hardware through a computer program. The program can be stored in a non-volatile computer-readable storage medium. When executed, the program can include the processes of the above-described method embodiments. Any reference to memory, storage, database, or other media used in the various embodiments provided herein may include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), RAMbus direct RAM (RDRAM), direct RAMbus dynamic RAM (DRDRAM), and RAMbus dynamic RAM (RDRAM).

[0185] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0186] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

[0187] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for measuring the impedance of a circuit with an electromagnetic shielding film, characterized in that: The method specifically comprises the following steps: The placed circuit board with electromagnetic shielding film is photographed horizontally and vertically, and accurately positioned and identified to determine whether it is in the standard placement state; When the circuit board is in a standard placement state, visually scanning and defect analysis of the electromagnetic shielding film of the circuit board to be tested is performed to determine whether it is in a standard appearance state; When in a standard appearance state, the device automatically connects to multiple test points of the circuit board to be tested, executes a preset frequency sweep task to perform line impedance testing, and collects impedance test data; Analyze and compare the impedance test data based on the preset impedance specification data, and record the impedance test results; Fill in the data of the impedance test results according to the preset test report template, generate and upload the impedance test report; The horizontal and vertical alignment shooting of the placed circuit board to be tested with the electromagnetic shielding film affixed thereto, and the precise positioning and identification to determine whether it is in the standard placement state specifically include the following steps: Placement monitoring is performed on the circuit board to be tested with the electromagnetic shielding film affixed thereto, and after placement is completed, horizontal shooting signals and vertical shooting signals are generated; Performing horizontal shooting of the circuit board to be tested according to the horizontal shooting signal to obtain a horizontal shooting image; According to the vertical shooting signal, vertically shoot the circuit board to be tested to obtain a vertical shooting image; Performing height recognition on the horizontally shot image and positioning recognition on the vertically shot image to determine whether the image is in a standard placement state; The method of performing height recognition on the horizontally shot image and positioning recognition on the vertically shot image to determine whether the image is in a standard placement state specifically includes the following steps: Perform edge detection on the matrix of the horizontally shot image to find the highest and lowest positions of the edge points in the horizontally shot image and calculate the height of the image. The corresponding process has the following relationship: ； in, Indicates the horizontal height, Indicates logical "existence", denote the rows and columns of the edge matrix respectively, Represents the edge matrix E Middle i Rank j The value of the column; Perform edge detection on the matrix of the vertically shot image, and calculate the weighted center position of the image by weighting the positions of the edge points. The corresponding process has the following relationship: ； in, represents the horizontal and vertical coordinates, represents the weighted horizontal coordinates of all edge points in the image, represents the weighted ordinates of all edge points in the image, represents the number of edge points, Indicates the n The weight of the edge points, Indicates the n The coordinates of the edge points; Calculate the variance of the horizontal and vertical coordinates of the edge points around the weighted center position to measure the stability of the center position. The corresponding process has the following relationship: ； in, represents the variance of the horizontal coordinates of the edge points, represents the variance of the vertical coordinates of the edge points, Define the height threshold, positioning tolerance, and variance tolerance to determine whether the circuit board is in the standard placement state. The standard placement judgment conditions are as follows: ； in, represents the height threshold, Indicates tolerance, Represents the height and width of the image respectively, represents the variance threshold; If all the above conditions are met, the circuit board is in the standard placement state; Wherein, when the circuit board is in the standard placement state, visual scanning and defect analysis of the electromagnetic shielding film of the circuit board to be tested are performed to determine whether it is in the standard appearance state, specifically including the following steps: When in a standard placement state, a visual scanning instruction is generated; Performing a visual scan of the electromagnetic shielding film on the circuit board to be tested according to the visual scanning instruction to obtain a plurality of visual scanning images; Cutting and splicing the plurality of visual scan images to obtain a standard visual image; Performing feature recognition on the standard visual image and recording feature recognition information; Performing defect analysis on the feature identification information to determine whether it is in a standard appearance state; Perform defect analysis on the feature recognition information to determine whether it is in a standard appearance state. The corresponding process has the following relationship: ； in, Indicates that defect analysis operations are performed based on the feature recognition information set extracted from the standard visual image, the feature information set of the standard template, and the additional feature set extracted from the standard visual image. Represents a set of feature recognition information extracted from standard visual images, Represents the feature information set of the standard template, represents a set of additional features extracted from standard visual images, Represents a set of all feature points in the feature recognition information set, Indicates the l Feature identification information, Indicates the l Template feature information, Indicates the l Additional feature information, Indicates the l Feature recognition information and l The distance between the template feature information, Indicates the l Additional feature information is used for weight calculation. Represent the weight coefficients of balancing feature recognition information and additional feature information respectively; Indicates the threshold value, used to determine whether it is in the standard appearance state; Indicates the number of features in the feature recognition information set.

2. The impedance testing method for a circuit with an electromagnetic shielding film according to claim 1, characterized in that: When the circuit board is in a standard appearance state, the plurality of test points of the circuit board to be tested are automatically connected, a preset frequency sweep task is executed to perform a line impedance test, and collecting impedance test data specifically includes the following steps: When in the standard appearance state, generate a test connection instruction; Automatically connect multiple test points of the circuit board to be tested according to the test connection instruction; Execute the preset frequency sweep task to perform line impedance test; During the line impedance test process, impedance test data is collected; The method for executing a preset frequency sweep task to perform line impedance testing specifically includes the following steps: The frequency sweep signal is generated by the frequency sweep signal generation formula f and time t The corresponding process of the sinusoidal signal under the following relationship exists: ； in, Indicates the frequency f and time t The sinusoidal signal below, represents the amplitude of the signal, Indicates frequency, Indicates time, Indicates the initial phase of the signal; Input a sinusoidal signal into the circuit board to be tested, and obtain the voltage and current signals through measurement. The corresponding process has the following relationship: ； ； in, Indicates the frequency f The voltage signal measured below is Indicates the frequency f The current signal measured below is represent the amplitudes of voltage and current signals respectively, denote the phase angles of voltage and current signals respectively, represents the phase portion of the voltage response, represents the imaginary unit, represents the phase portion of the current response, represents the exponential function; By using the impedance calculation formula, the voltage and current signals are divided by their amplitudes, and the phase difference is calculated to obtain the impedance value at the frequency. The corresponding process has the following relationship: ； in, Indicates the frequency f The impedance calculated below.

3. The impedance testing method for a circuit with an electromagnetic shielding film according to claim 1, wherein: The analysis and comparison of the impedance test data based on the preset impedance specification data and recording the impedance test results specifically include the following steps: Performing impedance analysis on the impedance test data to obtain characteristic impedance data; Performing standing wave ratio analysis on the impedance test data to obtain standing wave ratio data; Based on the preset impedance specification data, the characteristic impedance data and the standing wave ratio data are compared, and the impedance test results are recorded.

4. The impedance testing method for a circuit with an electromagnetic shielding film according to claim 3, characterized in that: The method of filling data of the impedance test results according to the preset test report template, generating and uploading the impedance test report specifically includes the following steps: Get impedance test time; Generate a current report template according to the impedance test time and a preset test report template; Filling data of the impedance test result in the current report template to generate an impedance test report; Upload the impedance test report according to the preset upload address.

5. An impedance testing system for a circuit with an electromagnetic shielding film, characterized in that: The impedance testing method for a circuit with an electromagnetic shielding film as described in any one of claims 1 to 4 above is applied, wherein the system includes a precise positioning and identification unit, a shielding film defect analysis unit, a circuit impedance testing unit, an impedance test analysis unit, and a report generation and uploading unit, wherein: The precise positioning and identification unit is used to take horizontal and vertical alignment photos of the placed circuit board to be tested with the electromagnetic shielding film attached, and to perform precise positioning and identification to determine whether it is in the standard placement state; a shielding film defect analysis unit, configured to perform visual scanning and defect analysis of the electromagnetic shielding film of the circuit board to be tested when the circuit board is in a standard placement state, to determine whether the shielding film is in a standard appearance state; A line impedance test unit, configured to automatically connect to multiple test points of the circuit board to be tested when in a standard appearance state, execute a preset frequency sweep task to perform line impedance testing, and collect impedance test data; An impedance test analysis unit, configured to analyze and compare the impedance test data based on preset impedance specification data, and record the impedance test results; The report generation and uploading unit is used to fill in the data of the impedance test results according to the preset test report template, generate and upload the impedance test report.

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